Embryology - Formation of the heart and great vessels

Question 1

What are the 5 layers of the heart tube from caudal to cranial end?

Answer 1

Left and right horns of Sinus Venosus
Atrium
Ventricle
Bulbus Cordis
Truncus Arteriosus

Question 2

When does the primary heart field form?

Answer 2

Week 3